Method of fitting tumbler pins



Oct. 9, 1951 R. c. CERF, JR

METHOD OF FITTING TUMBLER PINS 3 Sheets-Sheet 1 Filed Nov. 18, 194'? .v'l L FIG. 2.

t w as s INVENTOR ROBERT C. CERF JR.

FIG. 7.

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ATTORNEY Oct. 9, 1951 R. c. CERF, JR

METHOD OF FITTING TUMBLER PINS Filed Nov. 18, 194'? 3 Sheets-Sheet 2 FIG. 3.

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J m w N E V C N ITI R E B 0 R ATTORNEY Oct. 9, 1951 R. c. CERF, JR

METHOD OF FITTING TUMBLER PINS 3 Sheet s-Sheet 3 Filed Nov. 18, 1947 FIG. l l.

FIG.

INVEVNTOR ROBERT c. CERF JR.

ATTORNEY Patented Oct. 9, 1951 7 METHOD OF FITTING TUlVIBLER PINS Robert C. Cerf, Jr., Los Angeles, Calif., assignor to Hollymade Hardware Manufacturing Company, Los Angeles, Calif., a corporation of California Application November 18, 1947, Serial No. 786,727

2 Claims.

This invention relates to improvements in pin tumbler cylinder locks and in particular to a method for finishing and fitting the pins and key plugs of a cylinder lock.

One object of my invention is to provide an improved method for fitting pins in pin tumbler type cylinder locks. Another object is to provide a method to avoid filing and fitting pins by hand.

These and another objects are attained by my invention which will be understood from the following description and the accompanying drawings in which:

Fig. 1 is a side elevational view of my pin and plug grinding machine;

Fig. 2 is a top plan view of the same;

Fig. 3 is a cross-sectional view taken on the line 3-3 of Fig. 2; i

Fig. 4 is a cross-sectional View taken on the line 44 of Fig. 3;

Fig. 5 is a top plan view partly in section of the wheel dressing mechanism;

Fig. 6 is a cross-sectional View taken on theline 6-6 of Fig. 5;

Fig. 7 is a side elevational view of a pin tumbler key plug with protruding pins and inserted key, before grinding and fitting;

Fig. 8 is a top plan view'of an assemled cylinder lock of the removable type;

Fig. 9 is a side elevational View partly in section of the assembled lock shown in Fig. 8;

Fig. 10 is a typical cross-sectional view showing a key plug, an inserted key, and a rounded end tumbler pin, of the usual form made by hand filing;

Fig. 11 is a cross-sectional'view showing a key plug with an inserted key, a holefor a tumbler pin, a land around said hole, and a fiat end tumbler pin finished to a level with the land, of my improved form made by grinding;

Fig. 12 is an enlarged cross-sectional view taken on the line l2-l2 of Fig. 9; and

Fig. 13 is an enlarged fragmentary cross-sectional view showing the cylinder, driving pins, key, key plug, and a hand-filed rounded outer end tumbler pin.

It has been the usual practice, in finishing the transverse sliding tumbler pins of a cylinder lock having a key plug to insert the selected notched key (which is to be used for turning the key plug and operating the lock mechanism) into the key slot, put over-length tumbler pins in the holes in the plug, and then by hand filing to finish the pins so that the outer end point is in the plane of the cylindrical outer surface of the plug. Duringhand filing, the pins are turned axially so that y when finished, the plug maybe turned by the key no matter in what radial position the pins may be disposed in the holes. This results in a generally rounded end MA as shownparticularly in Figs. 10 and 13, with the rounded outermost point lying in the outer cylindrical surface of the plug, and with the margin generally below the plugs cylindrical surface. l-leretofore, no machine has been available to perform the filing of the tumbler pins to the proper end shape and length to be operated by a selected key. I have found that if a small level land is formed on the plug adjacent and surrounding the outer ends of the transverse holes for the tumbler pins, then the outer ends of the tumbler pins may be plane surfaces perpendicular to the axis of each hole and level with said land. When the plug-is thus modified, the tumbler pins may be fitted by grinding the ends flat and perpendicular to the land. This may readily be accomplished, and with precision by grinding off the over-length. tumbler pins simultaneously with the formation of the land around the holes for said pins, while keeping the notched key in place .in the key slot of the plug. This may be rapidly and economically carried out by the grinder machine of my invention. which is described in detail hereinafter.

Referring to the drawings, an improved trans! verse sliding pin tumbler cylinder lock of, the re-' moi-able type is shown in Figs. 8, 9, and 12, the cylinder body being provided. witha key plug 91 having transverse holes in which are fitted the tumbler pins 95 having fiat upper end surfaces IM level with theadjacent land 98 on the plug 91, said plug being adapted to be turned in the cylindrical opening in the body by the notched key I90 positioned in the key slot 99, only when the tumbler pins 95 are suitably positioned from their inner ends by the notches HH in the key I00, this turning of the plug. 9'! actuating the latching means through the spindle I82. The tumbler pins 95 are pressed against the key notches Iii l, by the corresponding driver.pins 93, which slide in holes in the driver .pin boss 9 l being held under the compression springs 94 which abut the slide cover I03 closing the outer end of the boss 9|. .When the p1ug9'l is turned to approach the position at which the key Hi0 may be withdrawn from the keyslot 99, the driver pins 93 .(whose contacting ends I05 are smoothly rounded) press at their tips upon the land 98 to give a slight clicking sound and a distinct feel to the fingers of the person who is turning the key. The key pull-out position is thus clearly and definitely indicated. With the conventional hand filed pins 95A in a plug 91A having no land (as shown for comparison in Figs. and 13), no click or feel is evidenced when the driver pins 93 and the tumbler pins 95A are in alignment, i. e. when the key I88 may be withdrawn, because the outer end I84A of the tumbler pins 95A, being filed tothe radius of the outer surface of the plug, ride smoothly under the substantially spherical ends I85 of the driver pins 93. The provision of the land on the key plug, and the forming of fiat outer ends on the tumbler pins not only solves the problem in operating the lock of positioning the plug for withdrawa1 of the key, but also permits the machine finishing of the plug and tumbler pins, and avoids the slow, tedious, and expensive old operation of hand filing the pins.

A preferred form of my plug and pin finishing grinder, shown in Figs. 1 to 6, consists of a frame II which is provided with a bed plate I2 upon which the machine is mounted, with a shelf I3 arranged below the bed plate I2 which serves to support the motor I4 and the gear reducing unit I5. The drive pinion I6 of the gear reducing unit I5 engages the main driving gear I! mounted on the shaft I8 which is supported in the bearing I9 mounted on the underside of the bedplate I2, the shaft I 8 extending through the bedplate I2. The shelf I3 is pivoted at one end by the pivot to a cross member II A of the main frame II, the opposite end of the shelf being supported on a cross member IIB of the main frame and being movable laterally by means of the cam lever 2| acting against one side of the shelf, the opposite side being provided with a compression spring member 22 acting against the shelf and the cam lever. This arrangement, permitting the lateral shifting of the shelf I 3, provides means for shifting the drive pinion I6 on the gear reducing unit I5 in and out of engagement with the main driving gear H. The revolving head of the machine, designated generally 24, is adapted to be rotated in a horizontal plane on the main shaft 25 which is fixedl mounted on the bed plate I2. A cylindrical hub or body, which is provided with four equally spaced radial arms 21, is mounted on thrust bearings 28 and 29 which are fitted on the main shaft 25. A ring gear 39 is attached by bolts 3! to the underside of the hub 26. The ring gear 38 is arranged to be driven by the pinion 33 mounted. on the end of the shaft I8. A bearing collar 32 is provided on the shaft 25 between the bed plate I2 and the thrust bearing 29 to hold the revolving head 24 above the bed plate I2, and a seal plate 34 is preferably provided, the two sealing rin s 35 extending into the corresponding groo es 36 on the lower face of the hub 26 to prevent the entrance into the thrust bearings 28 and 29 of metal chips and abrasive dust. Each of the radial arms 21 of the hub 26 is provided with a radial slot or recess 3'! in each of which is moun ed an arm 40 having a kev-holding finger 39 which at times is raised out of t e slot to hold a kev I09 inserted in a key slot 99 in a pin tumbler plug 91 which. in turn. is held. in a hole M in the plug holder 42 which is mounted on the up er edge of each rad al arm 21 of the hub 26. The arm 40 is pivoted to the wa l of the slot bv the pivot 39 and is nrovided with a short lever 43 which is adapted to be pressed hv the cam follower cylin er 4. he cyli d r 44 s m nt d to slide lon tu inahv in the h e 5 of the hub 2 t e opposite end of t e cam follower 44 being in contact with a cam 6;

mounted on the main shaft 25, the cam 46 having a cylindrical surface for about 225 of its circumference, the remainder of the surface being of reduced diameter allowing the arm 40 to be turned so that the key-holding finger 39 is projected out of the slot and against the end of the key I60 by the tension spring 47. The plug holder 42 is provided with the hole 41 which is adapted to receive a pin tumbler plug 91, and has an open slot on its upper side to permit the exposure of the overlength pins which are to be ground off in the operation of the machine. The cam follower 48 is adapted to engage a throw-out cam 49 in a hole 59 in the hub 26, the cam 49 being also mounted on the main shaft 25. The two cams 46 and 49 are preferably made as an integral sleeve keyed to the shaft by the key 52. The cam 49 consists essentially of a mini mum diameter cylindrical surface, with a single protruding portion of greater diameter, which acts against the cam follower 48 at times to push the plug 9'! from the hole 4| by means of the push-out rod 5| attached to the end of the cam follower 48, a compression spring 52 being provided to press the cam follower 48 against the cam 49. A cap 53 is conveniently provided over the upper roller bearing 28 being attached to the hub 26 by the bolts 54, this cap serving to prevent the entrance of abrasive dust and metal chips to the bearings.

The typical pin tumbler plug 91 with protruding pins 95 and an inserted key I60, which constitutes the assembly on which the grinding machine is adapted to work, is shown particularly in Fig. 7. The tumbler pins 95 are arranged in five holes at right angles to the plug axis so that the ends of the pins drop into notches IIlI in the key in accordance with any desired combination of notches. The overlength pins are then ground off so that the outer ends are level with an adjacent land 98 on the cylindrical plug 91. It will be clear that it is essential to have the key fully inserted in the key slot 99 of the plug 91 in order that the pins 95 may be leveled off to the surface of the land 98 and of proper length to allow rotation of the plug 91 by the key I08 in the cylindrical hole in the lock body 90.

A grinding wheel motor 56, having a vertically positioned grinding wheel 51 mounted thereon, is supported on the column 58 which is bolted to the bed plate I2 by bolts 59, the elevation of the motor and its grinding wheel being adjustable by the screw 60 which raises and lowers the bracket BI attached to the motor, the bracket being arranged to slide up and down in the dovetail slide 62 of the column 58. The screw 60 may be turned by means of the handle 63 mounted near the periphery of the graduated dial 64. A pointer 65 is provided with its tapered end adjacent the graduations on the dial 64 so that it may be used as an index of the amount of movement up and down of the grinding wheel 51. The weight of the motor and grinding wheel is counterbalanced by the tension of the counterbalancing spring 66 acting through the rods 6'! and 68 pivotally mounted at the opposite ends of the rocker arm 69 which is rockably mounted on the upright I0, the short arm 68 being attached to the attaching member II fastened to the screw 60. This counter balancing arrangement permits the grinding wheel to be raised slightly as it passes over the projecting ends of the pins which are to be filed off, without putting any undue strain on the grinding wheel shaft and motor..

- The lowest position of the grinding wheel surface is fixed on the screw 60 which is the low point to which the grinding off of the pins and the land on the plug is carried as the plug is carried under the wheel.

.The revolving head 24 is also provided with an additional radial arm 12 positioned intermediate two of the slotted radia1 arms 27. This arm is provided with a horizontally moving slide 7 3 upon which is mounted a vertically directed wheel dressing diamond '14 mounted in a holder 15 which is adjustably arranged in the clamping device 16 having set screws 71 and a vertical adjusting screw 73. When it is desired to dress the wheel, the main drive pinion I6 is disengaged from the driving gear I! by releasing the cam lever 2|, which permits the spring 22 to push the shelf I3 sidewise to disengage the main driving gear so that the head 24 is no longer revolved. The radial arm 12 is manually placed under the grinding wheel 51. The lead screw 79 which actuates the slide member 13 holding the diamond '14 is engaged through its slotted head 3|] by a forked rod 8| which is mounted horizontally in bearings 82 at the upper end of brackets 83, a crank wheel 34 with a handle 85 being provided on the rod 8|. A compression spring 86 is provided around the shaft 8| between the bracket 83 at one end and at the other end a collar 81 attached to the shaft 8|, this spring normally tending to keep the rod clear of the rotating head. When it is desired to move the diamond under the wheel, the rod 8| is engaged in the slotted head of the lead screw by pressing the crank wheel 84 in opposition to the spring. With the grinding wheel revolving in its usual manner, the diamond is passed across the wheel face to dress it to the desired true surface. The operation of dressing the wheel is carried out as often as necessary by interrupting the operation of grinding of the pins.

The method of operation of the machine will be apparent from the above description. The plugs with the keys in place and with the overlength pins in the pin holes are manually inserted in the hole 4| successively as the arms approach the grinding wheel. The cam 44 then actuates the key-holding finger 39 to raise it and press it against the end of the key so that as the pins pass under the grinding wheel, the key is firmly held in position, with the other ends of the pins in the key notches. When the plug with the pins ground off to a level surface or land pass beyond the grinding wheel, the finger 39 is released and the push-out rod 5| presses against the end of the plug to partly remove it from the hole 4| being actuated by the cam follower 48 and the cam 49. The finished assembly of plug, pins and corresponding key is then picked up by the operator and an unfinished assembly is inserted in the vacant hole 4|. The machine automatically, with a single operator, rapidly performs an operation which has heretofore been carried out by laboriou hand filing. The dressing of the surface of the grinding wheel is required only two or three times per day at the most.

The advantages of my invention will be apparent. By simultaneously forming the land on the plug, and grinding the ends of the pins to that level, the finishing and key fitting operation may be performed on a semi-automatic grinding machine and laborious hand filing of the pins is avoided. The tumbler pin and plug assembly, with fiat pins and the land, provides a pin tumbler cylinder lock of improved performance, and at lowered costs.

I claim:

1. The method of fitting tumbler pins in the key plug of a transverse sliding pin tumbler driver pin type cylinder lock to effect correspondence to a particularly notched key consisting of inserting overlength pins in the pin holes of said plug, holding the selected key in the key slot of said plug, and then grinding off the protruding end of said pins and simultaneously forming a land on the side of said plug adjacent said pin holes, the. outer ends of the pins being plane surfaced and made level with said land when the key is in place in the cylinder slot.

2. In the method of fitting a tumbler pin in a pin hole in the key plug of a transverse sliding pin tumbler and driver pin type cylinder lock, the step of grinding the protruding end of said tumbler pin and simultaneously forming a land on the side of said plug adjacent said pin hole, the outer end of the pin being plane surfaced and made level with said land.

ROBERT C. CERF, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,204,410 Christoph Nov. 14, 1916 1,231,720 Drake July 3, 1917 1,593,513 Stone July 20, 1926 1,677,432 Croning July 17, 1928 1,860,712 Gutman May 31, 1932 1,953,535 Hurd Apr. 3, 1934 1,979,939 Jacobi Nov. 6, 1934 2,345,189 Fraser Mar. 18, 1944 

